JPH04501281A - Residual oil decomposition method and equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Residual oil decomposition method and equipment Fluid catalytic cracking (FCC) is a mature process. This method is suitable for relatively heavy , usually converting distillable raw materials into more valuable lighter products. Oil refinery in recent years In the industry, more and more ``bottos of the barrel'' the barrel) J to more valuable light products, such as residual oil or residual oil There is an increasing need to convert to traction.

In the past, these heavy streams were processed through processes such as coking and visbreaking. It has been subjected to various heat treatments to convert it into more valuable products. generation of pyrolysis The product itself is a product of relatively low value, such as heavy fuel oil or coke from visbreaking. Unfortunately, it is coker naphtha or coker gas oil from a coking operation. However, heat treatment alone has not been identified as a complete answer to these problems. not present. In the case of coking, the production of very large amounts of coke results in large amounts of low-value production. It will bring about a product.

Residual oils contain a large proportion of refractory components that are difficult to decompose, such as polycyclic aromatic compounds. nothing. Residual oils also contain large amounts of metals that rapidly deactivate conventional catalysts. raw materials like this Attempts at contact processing, such as adding a relatively small amount of residual oil to a normal FCC feedstock Some things have been done. The FCC device collects a suitable amount of residue in the feedstock, e.g. 5-10% by weight is acceptable, but heavy feedstocks (high Conra dson) increases the combustion load of the regenerator due to its carbon content, and increases the combustion load of the regenerator due to its carbon content. poisons the catalyst. Limiting the amount of residual oil in FCC feedstocks requires regeneration operations. This is the method chosen when controlling the temperature, but adding a catalytic cooler Considerations have been made. The problem of nickel and vanadium contamination is Mobilization, e.g. adding antimony to the equipment to passivate the metals added with the feedstock This can be overcome to some extent by doing so. Passivation of the metal results in a relatively large amount of nitrogen. Although FCC units can be operated continuously using catalysts containing Kel and vanadium, this This is not a complete solution. Vanadium is used in the zeolite structure of recent FCC catalysts. It is thought that the catalytic activity of the catalyst is attacked, and as a result, the catalytic activity decreases rapidly. to vanadium Although the exact cause of the poisoning caused by Oxidized vanadium compounds are formed in an oxidizing atmosphere, and these It is believed that compounds, especially vanadate, attack the zeolite rapidly. this question The issue is vanadium poisoning of cracking catalysts. oning of Cracking Catalyst) Worssbecher et al., Journal of Catalysis (J) of Catalysis) Volume 100, pp. 130-137 (1 986)).

In most petroleum refining industries, the metal concentration of the catalyst is monitored and the catalyst is Discard and replace with new catalyst to control the average level of metals in the catalyst. Ru. Such measures can result in very high catalyst replacement rates. It's expensive.

Another method of adding residual oil to an FCC unit is described in U.S. Patent No. 3.886.06. It is stated in No. 0. Residual oil is used as cooling medium and riser conversion area limit the conversion of recycled oil in

The preferred catalyst is a two-component system, i.e. a large pore size zeolite and a small pore size zeolite. Contains zeolite. Operated with a single regenerator with two risers.

Despite the many improvements that have been made, mainly due to the large quantities involved in such raw materials. Attempts to break down residual oil for metals and coke have not been successful enough. . We use a two-stage regenerator to solve such difficult problems in a single riser reactor. We found a way to handle raw materials. This method uses a single lamp with a two-stage regenerator. Special results are obtained using coarse and conventional catalysts in the Iser reactor.

By careful selection of catalyst dimensions and superficial vapor velocity during catalyst regeneration, It becomes possible to efficiently separate and retain coarse catalyst from other catalysts. The coarse catalyst is , minimizes the oxidation of vanadium compounds on the catalyst, but increases the hydrogen content of the coke. Regeneration in one step under relatively mild conditions that removes most of the water precursors. be done. Typical FCC catalysts are somewhat regenerated in the first stage regenerator and then more It is subjected to a second stage of regeneration at a higher temperature with a higher oxygen concentration. two different types The use of a catalyst in a two-stage regenerator allows for significantly higher metal levels in the feedstock. I can tolerate it.

The present invention utilizes a riser reactor in which heavy metal-containing raw materials are subjected to hot regenerated catalytic cracking. The raw material is cracked into lighter products, and the cracking catalyst also includes coke. The catalyst is separated from the decomposition products by a separation means, and the coke-adhered catalyst is The stripping gas strips the strippable hydrocarbons and The recycled catalyst is regenerated with oxygen-containing gas in the regeneration area, and the regenerated catalyst is Provides a fluid catalytic cracking method that is recycled to the riser and further contacts heavy raw materials. , this method is a) a fluidizable catalytic cracking catalyst with a certain settling rate and a settling rate greater than the cracking catalyst; Heavy feedstock in a riser reactor using a writable mixture of additives with a descending rate b) the additives and the decomposition catalyst are separated into a lower concentration enriched with the additives; It has a single dense phase fluidized bed forming a thick phase bed and an upper dense phase bed rich in cracking catalyst. The method is to feed the writable mixture into a regenerator consisting of Then, the first oxygen-containing gas is added to the upper rich bed, and the cracking catalyst is regenerated in the upper rich bed. A second oxygen-containing gas is added to the lower concentrated bed rich in additive materials to reduce coke from the additive materials. to remove at least part of the spider; C) At least partially coke-free additive material enriched downwardly with additive material Remove from bed and recycle additive material to riser reactor to contact feedstock and d) separately removing the regenerated cracking catalyst from the upper rich bed and removing it. The feature is that the discharged catalyst is recycled to the riser reactor.

In an apparatus aspect, the invention provides an apparatus for fluidized bed combustion of a receptable mixture of particles. , the device is Inlet for adding particulate mixture, lower combustion gas for introducing combustion air Upper combustion gas inlet for introducing additional combustion air into the upper part of the combustion area mouth, Lower particle outlet for removing particles from the lower part of the combustion zone, particles from the combustion zone an intermediate particle outlet located above the lower outlet for removing Upper outlet for removing flue gases produced by combustion in the fluidized bed The vessel comprises a vessel having:

FIG. 1 shows a prior art FCC regenerator using a single dense bed.

The FCC regenerator l receives spent catalyst from the FCC unit via line 4o. Ru. Combustion air is added via line 1o and air grid 20. child The air burns the coke in the catalyst. The hot regenerated catalyst is It is removed via line 30 for reuse in the reactor. produced during coke combustion The resulting flue gas is passed through a cyclone 50. (which recovers the entrained FCC catalyst). Plenumchi It is discharged via the chamber 60 and the output lower o.

FIG. 2, which illustrates one preferred embodiment of the invention, shows an improved FCC regenerator 1 (regenerator). The outer shell of the vessel can be considered to be (identical to that of prior art regenerators); Therefore, in FIGS. 1 and 2, the same elements have the same reference numbers). Used A mixture of heavy vanadium uptake additives with saturated catalyst and coke is is added to the regenerator via channel 40. Relatively heavy or large vanadium uptake The additive settles faster than normal FCC catalyst, so it settles to the bottom of the regenerator 1.

This uptake additive is routed through line 210 and distributor located just at the base of the regenerator. Coke is removed at the base of the regenerator by adding a second air via ring 220. removed. Uptake additives provide some coke removal, but some coke Preferably, it contains coke, for example 0.1% by weight or more.

Primarily processes heavy residual oil feedstocks containing large amounts of Conradson carbon and similar materials. Since the combustion load of the regenerator increases due to the temperature tends to become very high. When the additives descend into the base region 250 of the FCC regenerator, It is preheated to some extent as it passes through a dense bed 260 of conventional catalyst.

A typical catalyst is primarily charged via the inlet 110 and the first air ring 120. The first combustion air obtained is regenerated in the rich bed 260. The regenerated catalyst is via line 130 and preferably to the FCC riser reactor. It is discharged at an intermediate point.

A steam coil 270 is installed in the lower region to remove some of the excess heat in the regenerator. Preferably, it is present at 250. Add catalyst to region 250 via line 330. or from there to a cooler or heat exchanger (not shown). d The lower region 250 is more clearly defined and relatively light catalysts are separated. Filler or spacer 220 to separate the lower region from the upper region 260 is illustrated. The filler or insert 220 is used to absorb the overhead vapor in the regenerator. Uptake additions that give a relatively large change in velocity and thus settle relatively quickly Improved woodblock separation from conventional FCC catalysts with more easily fluidized agents .

The partially decoked additive particles are routed to the riser reactor via line 230. In addition, regenerated conventional FCC catalyst is added to the base (bottom) of the Preferably added in a somewhat higher section of the iser reactor, the decoked addition Add the mixed stream to the base of the riser reactor by mixing the agent and regenerated catalyst. It is also within the scope of the present invention to

In the riser reactor, the decoked uptake additive is It has a long residence time. This is because coke removal additives have much higher sedimentation rates, Preferably, a settling velocity of 50 to 100% of the superficial vapor velocity at the base of the riser reactor. This is because it has a certain degree.

The base of the riser reactor (reducing the superficial vapor velocity and incorporating new additives) widened (to give additional contact time with the raw material) or straight There may be. It is also within the scope of this invention to feed the FCC riser reactor in portions. Ru. When feeding in parts, the highest metal content and highest OCR content ( Feedstock with Conradson residual carbon is first added and brought into contact with additives. let The normal feed and normal hot regenerated FCC catalyst are then fed into the riser May be added to higher positions.

It is generally preferred to have at least one method of removing heat from the regenerator. Second Although the steam coil is shown only in area 250 of the diagram, the area above the regenerator's rich bed 260 or in the dilute phase region of the regenerator I. It is. From the decoked particles in line 230 using a catalyst cooler, Alternatively, heat may also be removed from the regenerated catalyst removed via line 130.

Adjusting air addition and subsequent coke combustion along with heat removal from the regenerator, It is preferable to heat the decoked uptake additive much hotter than a typical FCC catalyst. Delicious. High temperature decoked uptake additives are recommended for raw materials containing heavy residual oils. It is very efficient in evaporating metals and quickly (removes metals from raw materials. Conventional cracking catalysts are often added near the same location as the decoked uptake additive. , or even higher on the riser, it may be at a somewhat lower temperature. , quenching the thermochemical reaction caused by hot coke removal and uptake additives do. There may be a very sharply formed hot area at the base of the riser; The riser is then heated by the somewhat cooler regenerated catalyst at a higher point in the riser. or other hydrocarbon streams higher up the riser. The riser is rapidly cooled by adding Other relatively cool hydrocarbon streams When adding vapor or other vaporizable fluids, e.g. water, higher up the riser, A desired temperature distribution can be formed on the riser.

Simply rinse the relatively hot uptake additive and the somewhat colder regenerated FCC catalyst. When added to the base of the iser, the area around the normal decomposition catalyst is somewhat colder and the High temperature areas may be localized in the area around the additive.

Conventional catalysts and uptake additives are freely mixed in the riser and separated in the regenerator. provides a very simple and reliable means of removing metals from residual oil feedstocks by It can be achieved. Some of the conventional catalyst is entrained in the entrained additives and passes through region 250. , via line 230 to the base of the riser where it contacts the fresh residual oil-containing feedstock. Because of the relatively large amount of entraining additive present when contacting the metal, conventional catalysts This system is relatively fail-safe in that it provides some protection from fouling. (danger prevention). Typical FCC catalyst and uptake additives together are F CC riser reactor, passed through a regular stripper and returned to the regenerator where the separation have the opportunity to be treated again.

If some uptake additive flows into the FCC catalyst return line 130, it simply It simply passes through the riser reactor and is finally incorporated along with other uptake additives. is separated into an additive bed 250.

Most uptake additives, preferably 90% or more uptake additives are The relatively reducible It is played in an atmosphere of This results in the production of highly oxidized vanadium. is the minimum. The coke removal of the uptake additive in bed 250 is relatively low. Occurs in the humidity region. Most of the water in the FCC regenerator is water from combustion (by combustion of hydrogen) and the stream entrained in the catalyst entering the regenerator. Derived from ping steam. These two sources of water essentially cover the entire The tripping steam is removed as the entrained additive passes through bed 260. However, in the present invention, most of them are removed. Much, perhaps most, of the hydrogen in the coke Also, as it descends into bed 250, there is a relatively short flow of entrained additive in bed 260. burns during a short residence time.

The method of the present invention provides a catalyst that minimizes the generation of both NOx and carbon monoxide. It is extremely efficient in regenerating. This is designed to minimize the generation of NOx. This is an unusual action in terms of maximizing carbon monoxide production.

The generation of NOx is caused by operating the rich bed section 250 of the regenerator in a relatively reducing atmosphere. This will be minimized. This minimizes the generation of NOx. lots of monoxide Carbon will be produced (usually as a result of combustion in bed 250 - oxidized carbon (there will be an equimolar mixture of carbon dioxide and carbon dioxide). This is usually acceptable. However, CO is generated in a large amount without being post-combusted in the lean phase part of the regenerator. - The carbon oxide can be completely combusted in the rich bed 260. add additional air (first air added via line 110 and first air ring 120) Also, since a CO combustion accelerator can be present in the system, CO can be used as an afterburner. Can be baked. CO combustion promoters, such as platinum on alumina, are or as a solution of chloroplatinic acid added to the circulating catalyst. Standard 0.01-50 ppI6. Preferably 0.5 to 5 pp-by weight platinum is well known. The method of the invention uses a CO combustion promoter, in particular the granules of a conventional FCC catalyst. Highly efficient use of pt-alumina additives with particle sizes similar to the child size Wear. These CO combustion enhancers collect in bed 260. As a result, the air population 2 10 and the addition of the second air via air ring 21O is less precise. good. Dense beds due to poor distribution and poor control of the amount of air added There is no risk of afterburning above 250. All air passing through inlet 210 Bed 2 is used for conventional FCC catalyst regeneration and combustion of carbon monoxide produced in Bed 250. Consumed at 60.

Most coke combustion processes feature a relatively reducing atmosphere that minimizes the production of NOx. Since this occurs in the characteristic region 2.50, NOx generation is minimized in the present invention.

Although not shown, in addition to the regular steam stripper, there is also a hot stripper. is preferably used intermediate the conventional catalyst stripper and the regenerator of the present invention.

The catalyst stripper can be made hotter by adding flue gas or hot regenerated catalyst. Relief The use of toss strippers increases the recovery of valuable liquid hydrocarbon products and This is preferred because it reduces the amount of hydrocarbons burned. Also a hot stripper plays Reduce the amount of water produced by combustion in the vessel.

The present invention can be applied to many existing single-non-regenerators by making the following changes. Easy to implement.

First, the core region is filled with a filler material such as element 220 of FIG. The diameter (area) of the core region is significantly reduced while raising the air grid. of the present invention The air outlet will not supply that much air, so it should be light and small. You can make it.

Preferably, the overflow basin is raised somewhat and the active catalyst is placed mid-point on the riser. Discharge. Some modification of the riser is required to accommodate the two catalyst feed points. Of course, there is a need. Coarse addition when operating at higher average bed depth in the regenerator accommodating agents or “uptake agents”. New catalyst circulation lines (e.g. In230) is added to the bottom of the core with low activity (inert or metal "uptake agent") Recycle particles to the base of the riser. Steam generation coil in the modified conical part It is preferable to add 270 (or connect a new catalyst cooler). catalyst A good place to locate the cooler will allow the particles to fluidize easily and smoothly, making it easier to reuse. This is the return line for the raw catalyst.

A new air ring (e.g. ring 220) is attached to the conical portion to remove the bulk, e.g. Supply 50-90% air. This spans a depth of 1, not a ring. It may be a "sparger" that blows air into the fine FCC catalyst. More efficient separation from larger particles.

The catalyst may be a conventional FCC catalyst. Its particle size or average diameter is 30-1 00 microns.

Preferably, the additive material has a high affinity for metals, such as vanadium. Yes. Larger particles of relatively soft alumina are preferred. Preferably, adding The agent is less than the decomposition catalyst (both 20% greater and most preferably 100% greater). having an average particle diameter and an average bulk density at least 10% greater than the cracking catalyst. preferable.

The feedstock may be conventional, but with the exception of recycled streams, large amounts of residual oil , asphalt, etc., for example, when the raw material is 10 to 100% residual oil, The greatest economic benefits are realized.

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Claims (13)

[Claims] 1. In the riser reactor, heavy metal-containing feedstock contacts a hot regenerated catalytic cracking catalyst. The raw material is decomposed into lighter products, and coke adheres to the cracking catalyst. The catalyst is separated from the decomposition products by a separation means, and the coke-adhered catalyst is separated from the decomposition products by a separation means. The strippable hydrocarbons are stripped by the stripping gas. The regenerated catalyst is regenerated with oxygen-containing gas in the regeneration area, and the regenerated catalyst is transferred to the riser. A fluid catalytic cracking method in which the heavy raw materials are recycled and further contacted with the heavy raw materials, a) a fluidizable catalytic cracking catalyst with a certain settling rate and a settling rate greater than the cracking catalyst; Heavy feedstock in a riser reactor using an elutriable mixture of additives with a descending rate b) the additives and the decomposition catalyst are separated into a lower concentration enriched with the additives; It has a single dense phase fluidized bed forming a thick phase bed and an upper dense phase bed rich in cracking catalyst. The elutriable mixture is fed to a regenerator consisting of Then, the first oxygen-containing gas is added to the upper rich bed, and the cracking catalyst is regenerated in the upper rich bed. A second oxygen-containing gas is added to the lower concentrated bed rich in additive materials to reduce coke from the additive materials. to remove at least part of the spider; c) At least partially coke-free additive material enriched downwardly with additive material Remove from bed and recycle additive material to riser reactor to contact feedstock and d) separately removing the regenerated cracking catalyst from the upper rich bed and removing it. A method characterized in that the discharged catalyst is recycled into a riser reactor. 2. Claims: The oxygen-containing gas added to the lower rich bed is added at multiple levels. The method described in paragraph 1. 3. The average diameter of the decomposition catalyst ranges from 30 to 100 microns, and the added material Claim 1, or The method described in Section 2. 4. Claims wherein the additive material has an average particle diameter at least twice that of the cracking catalyst The method described in Section 3. 5. The cracking catalyst has a certain average bulk density, and the additive material is at least as dense as the cracking catalyst. The method of claim 1 having a 10% greater average bulk density. 6. Any one of claims 1 to 5 in which a CO combustion additive is added to the catalytic cracking catalyst. Method described. 7. A nearly reducing atmosphere is maintained in the lower concentrated bed, and the additive material extracted is Claims 1 to 6 containing at least 0.1% by weight of coke after coke removal The method described in any of the paragraphs. 8. 10-50% of the total amount of oxygen-containing gas added to the regenerator is concentrated 50-90% of the total amount of oxygen-containing gas is added to the thick bed enriched with cracking catalyst. 8. A method according to any of the appended claims 1-7. 9. The heat exchange means includes an upper rich bed, a lower rich bed, a regenerated cracking catalyst to be removed, and removing heat from at least one of the additive substances removed; The method described in any of Item 8. 10. The lower dense bed of the regenerator has a reduced cross-sectional area with respect to the upper rich bed. The method according to any one of items 1 to 9. 11. An apparatus for fluidized bed combustion of an elutriable mixture of particles, comprising: a) an elutriable mixture of particles; b) lower combustion gas inlet for introducing combustion air, c) ) an upper combustion gas inlet for introducing additional combustion air into the upper part of the combustion area; d) a lower particle outlet for removing particles from the lower part of the combustion zone; e) a lower particle outlet for removing particles from the lower part of the combustion zone; an intermediate particle outlet located above the lower outlet for removing particles from the f) upper outlet for removing flue gases produced by combustion in the fluidized bed; A device comprising a vessel having: 12. The vessel has a reduced cross-sectional area with respect to the cross-sectional area at the intermediate particle exit. 12. The device according to claim 11, having at the particle outlet. 13. 12. A device according to claim 11, wherein heat exchange means are present within the device.